Face and Head Shield

ABSTRACT

A protective shield features a single-piece transparent dome or shell having a rear opening through which facial and cranial regions of a user&#39;s head are received, thereby providing improved coverage over conventional face shields that cover the face only. Inward protrusions at a transitional region between the facial and cranial portions of the shield rest against the forehead to offset the facial portion of the shield forwardly of the user&#39;s face to allow airflow, optionally introduced from an external fan via an airflow channel integrally formed in the cranial portion. A flexible connector clip has a J-shaped profile for engaging an out-turned flange around the boundary of the shield s rear opening, to enable clipped connection of a bib or shroud. Support protrusions in an underside of the cranial portion maintain airspace above the head, which is further optimized by a rearwardly sloped incline of the cranial portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority benefit of U.S. Provisional Patent Applications 63/002,340 filed Mar. 30, 2020; 63/005,140 filed Apr. 3, 2020; 63/020,501 filed May 5, 2020; and 63/059,739, filed Jul. 31, 2020; each of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to personal protective equipment, and more specifically to protective facial shields.

BACKGROUND

The current COVID-19 outbreak demonstrates the significant demand for adequate personal protective equipment (PPE) for medical personal who risk potential exposure to contagions when treating infected patients. A face shield used in such context is conventionally composed of a panel of transparent polymeric material worn in curtain-like fashion hanging in front of the user's face via an attached supportive headband or visor worn at forehead level. The panel is curved in a horizontal direction across the wearer's face, so that a central region of the panel resides anteriorly of the wearer's face over the eyes, nose and mouth, and lateral regions of the panel curve posteriorly from this central region to at least partially cover the side of the face. The shield itself typically terminates at an upper edge of the panel situated at, or shortly above, the shield's attachment to the headband or visor, leaving at least part of the forehead and the user's hairline exposed, especially if a separate protective cap or other head cover is not also worn. Such inadequate coverage at the upper facial area, together with gaps left between the shield and the wearer's face where the lateral regions terminate at upright lateral edges of the panel, leaves the user at risk of exposure to droplets or aerosol particles emitted by a sneezing or coughing patient. More adequate coverage than that provided the shield itself thus conventionally requires donning of additional protective gear.

Accordingly, there is a need for improved solutions to address this and/or other shortcomings of conventional face shields.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided a face and head shield comprising a transparent non-spherical dome or shell delimiting a hollow interior space for receiving facial and cranial regions of a user's head therein, said non-spherical dome or shell having a boundary edge thereof that delimits an opening of said hollow interior space through which said facial and cranial regions of said user's head are admitted into said hollow interior space, said opening having an elongated primary dimension measured in one direction thereacross and configured with sufficient length to accommodate a chin-to-crown measurement of the user's head in inferior-superior anatomical direction, and a shorter secondary dimension measured cross-wise to said primary dimension and configured with sufficient length to accommodate a narrower width measurement of the user's head in a lateral anatomical direction.

According to another aspect of the invention, there is provided a method of protecting against exposure to a hazard, said method comprising obtaining a plurality of face and head shields each configured to cover both facial and cranial regions of a user's head, wearing a support frame on said user's head on an ongoing basis, and during said wearing of said support frame on said ongoing basis, intermittently swapping out a worn one of said plurality of face and head shields for a replacement one of said face and head shields.

According to yet another aspect of the invention, there is provided a protective shield for shielding facial and cranial regions of a user's head, said protective shield comprising a singular unitary piece of transparent material comprising an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and at a transitional region that joins said lower facial and upper cranial portions, at approximately forehead level when said protective shield is worn, a pair of inward protrusions jutting inwardly from the transitional region relative to surrounding inner surface areas thereof, and an airflow space whose width is delimited between said pair of inward protrusions, said airflow space having a widened lower end that coincides with bottom ends of said inward protrusions, and from which said airflow space tapers upwardly to a lesser width than said widened lower end.

According to yet another aspect of the invention, there is provided a protective shield for shielding facial and cranial regions of a user's head, said protective shield comprising a singular unitary piece of transparent material comprising an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, and a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and in a cross-sectional measuring plane that is either a midplane that bisects the cranial and facial regions, or another plane that lies parallel to said midplane, a slope of the lower facial portion toward the bottom end of the dome or shell and a slope of the upper cranial portion toward the top end of the of the dome or shell are of divergent relationship to one another over an entirety of each of said upper cranial and lower facial portions.

According to yet another aspect of the invention, there is provided a protective shield for shielding facial and cranial regions of a user's head, said protective shield comprising a singular unitary piece of transparent material comprising an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, said single unitary piece of see through material stiffening ridges formed therein at opposing lateral sides thereof in matching orientations extending rearwardly away from the facial region toward.

According to a further aspect of the invention, there is provided a protective shield for worn use on a user's head to protect facial and cranial regions thereof, said protective shield comprising:

-   -   a piece of transparent material comprising an upper cranial         portion arranged to overlie a top of the user's head, at least         at a frontal scalp thereof, and a lower facial portion arranged         to hang downwardly from the cranial portion over the facial         region of the user's head;     -   wherein said upper cranial portion has an airflow channel formed         therein, said airflow channel having opposing inlet and outlet         ends situated respectively distally and proximally, with the         outlet end being open to an interior space of the protective         shield at or near the facial region thereof so that airflow fed         through the inlet end of the airflow channel is directed into an         air space between the shield and the facial region of the user's         head.

According to another aspect of the invention, there is provided a protective shield for worn use on a user's head to protect at least a facial region thereof, said protective shield comprising:

-   -   a shield piece sized to span at least said facial region in both         superior-inferior and lateral directions;     -   at a region of said shield piece arranged to reside at generally         equal elevation to a forehead of the user's head when said         shield piece is donned in a worn position, and at an exterior of         said piece of said shield piece that faces outward from the         user's head in said worn position, an uncovered external support         surface arranged to jut anteriorly outward from the forehead of         the user in said worn position to accommodate mounting of one or         more accessories atop said external support surface at said         exterior of the shield piece.

According to yet another aspect of the invention, there is provided a protective shield for worn use on a user's head to protect at least a facial region thereof, said protective shield comprising:

-   -   a piece of transparent material sized to span at least said         facial region in both superior-inferior and lateral directions;     -   an out-turned flange projecting from a boundary edge of the         piece of transparent material around at least a partial         perimeter thereof; and     -   a flexible connector clip configured to clip to said shield at         said out-turned flange and to support a bib or shroud thereon.

According to yet another aspect of the invention, there is provided a protective shield for shielding facial and cranial regions of a user's head, said protective shield comprising a singular unitary piece of transparent material comprising an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and one or more support protrusions that are integrally formed in, or attached to, said cranial portion and jut downwardly from an underside thereof relative to surrounding surface areas of said underside of the cranial portion for resting of said support protrusions against the top of the user's head so as to support said surrounding surface areas in elevated relation over the top of the user's head to enable airflow therebetween.

According to yet another aspect of the invention, there is provided a one-piece adjustable length headband for support of a protective shield on a users head, said headband comprising a singular unitary strip of foam material having al length dimension in which said strip of foam material is elongated relative to width and thickness dimensions thereof that are orthogonal to both one another and to said length dimension, said strip of foam material having opposing first and second ends between which said length dimension is measured, said strip of foam material having a barbed tail region spanning a partial length of the length dimension from the first end toward the second end, and a widened end region that resides adjacent the second end and is of greater measure in the width dimension than said barbed tail region, said strip of foam material being flexibly bendable in said length dimension to bring the first and second ends toward one another to form a closed loop, said barbed tail region being barbed on opposing sides thereof, and said the widened end region having at least one receiver opening therein through which the first end is insertable to engage the barbed tail through said receiver opening, whereupon the barbed sides of the barbed tail region resist pulling of the first end back through said receiver opening, thereby securing the headband in said closed loop, which is adjustable in size by pulling more of the barbed tail onward through said receiver opening.

According to yet another aspect of the invention, there is provided a two-piece adjustable length headband for support of a protective shield on a users head, said headband comprising a first strip of foam material having a first pair of opposing ends separated from one another by a length dimension of said first strip of foam material, and a second strip of foam material having a second pair of opposing ends separated from one another by a length dimension of said second strip of foam material, one of two widthwise faces of the first strip having a respective piece of hook or loop fastener thereon adjacent each of the first pair of opposing ends, and one of two widthwise faces of the second strip having a respective piece of loop or hook fastener thereon adjacent each of the second pair of opposing ends that is matable with one of the hook or loop fasteners on the first strip, whereby the first and second strips are connectable face-to-face in end-overlapping fashion to form a closed loop, and at least one of the pieces of fastener is elongated in the length dimension of the respective strip of foam material to enable coupling together of the two strips in varying degrees of overlap to thereby adjustably size said headband.

According to yet another aspect of the invention, there is provided a method of using, in combination, a protective shield for covering at least a facial region of a user's head, and a headband for worn support of said protective shield on said user's head, wherein said protective shield, at an elevation configured to reside at approximately forehead level on the user's head when worn, has a pair of inward protrusions jutting from surrounding inner surface areas of said protective shield at laterally spaced positions from one another so as to span toward and brace against a forehead of the user's head at laterally spaced positions thereacross when worn, and said headband comprises a length of foam coupled to terminal ends of said pair of inward protrusions for foam-padded abutment of the pair of inward protrusions against the forehead when the headband and protective shield are worn on the user's head, and the method comprises cutting out a section of said foam between said pair of inward protrusions to enable airflow through said cut out section of the headband when worn.

According to yet another aspect of the invention, there is provided a protective shield for shielding facial and cranial regions of a user's head, said protective shield comprising a singular unitary piece of transparent material comprising an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and at a transitional region that joins said lower facial and upper cranial portions, at approximately forehead level when said protective shield is worn, at least one inward protrusion jutting inwardly from the transitional region relative to surrounding inner surface areas thereof, wherein, in a cross-sectional measuring plane that is parallel to a midplane that bisects the cranial and facial regions, at least a partial region of the lower facial portion has a linear slope, and at least a partial surface of a distal end each inward protrusion has a relative slope of obliquely oriented and downwardly convergent relationship to said linear slope of the lower facial portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a head and face shield and cooperating support frame according to a first embodiment of the present invention, shown in an assembled state for use.

FIG. 2 is another perspective view of the shield and support frame of FIG. 1 , but shown in a disassembled state to illustrate the removability of the head and face shield from said support frame.

FIG. 3 is a perspective view of the shield and support frame of FIG. 1 during use, as viewed from an anterior/inferior (front/bottom) perspective.

FIG. 4 is another perspective view of the shield and support frame of FIG. 3 , but from a lateral/superior (side/top) perspective.

FIG. 5 illustrates manufacture of the shield by vacuum forming thereof over a suitably shaped form.

FIG. 6 illustrates the formed shield of FIG. 5 after removal thereof from said form.

FIGS. 7A through 7E illustrate attachment of an optional front bib to the head and face shield of the preceding figures.

FIG. 8 illustrates attachment of an optional full-circumference shroud to the head and face shield to provide more comprehensive coverage that the front bib of FIG. 7 .

FIGS. 9A, 9B and 9C are side, front and top views of a second embodiment of the head and face shield.

FIGS. 10A, 10B and 10C are perspective, front and rear views of a third embodiment of the head and face shield, and FIG. 10D is a cross-sectional view thereof as taken lone line D-D of FIG. 10C.

FIGS. 11A and 11B are exploded and assembled views illustrating installation of airflow channel components on the head and face shield of FIG. 10 , and FIG. 11C illustrates connection of the finished airflow channel to a source of forced supply air.

FIG. 11D illustrates the shield of FIG. 11C in use with an attached shroud equipped with a pass-through port via which an air supply conduit is routed between the airway channel of the shield and the source of forced supply air.

FIGS. 12A through 12E are front perspective, top-front perspective, side elevational, front elevational and rear perspective views of a variant of the third embodiment shield of FIGS. 10 and 11 , and of which FIG. 12C illustrates optional use of a top ledge of a bumped-out lower facial portion the shield to support a headlight or other accessory.

FIG. 13A shows the cross-sectioned shield of FIGS. 10D and 11C, but equipped with a variant of the airflow channel components of FIG. 11 .

FIG. 13B is an exploded perspective view of the variant airflow channel components of FIG. 13A;

FIG. 13C is a partial closeup view of one of the variant airflow channel components of FIG. 13B.

FIG. 14A is a rear perspective view of the shield of FIG. 12E with a flexible attachment clip installed on a flanged boundary edge around a rear opening of the shield.

FIGS. 14B and 14C are fragmentary perspective and cross-sectional views of the flexible attachment clip of FIG. 14A, illustrating one possible profile thereof, with FIGS. 14D and 14E being matching views showing a slight variation in said profile.

FIGS. 15A, 15B and 15C are front perspective, side elevation and top-front perspective views of a final fourth embodiment of the head and face shield.

FIGS. 15D and 15E show cross-sectional profiles of the shield of FIG. 15C as cross-sectioned along lines D-D and E-E thereof, respectively.

FIG. 15F is a rear elevational view of the shield of FIGS. 15A through 15E.

FIG. 16 illustrates the cross-sectioned shield of FIG. 15E in a worn position on a user's head.

FIG. 17A is a top plan view of an adjustable one-piece foam headband of the present invention, laid out flat before curling thereof into a closed loop wearable around a user's head.

FIG. 17B is a top plan view of the adjustable one-piece foam headband once curled into a closed loop and secured in this closed state using a barbed tail of the headband.

FIG. 17C is a rear perspective view of the adjustable one-piece foam headband installed on one of the shields, with the headband in an open state ready for placement around a user's head.

FIG. 17D is another rear perspective view of the headband and shield of FIG. 17C, but with the headband secured in the closed state using the barbed tail of the headband.

FIG. 18A illustrates an adjustable two-piece foam headband of the present invention, prior to assembly and installation thereof on a shield.

FIG. 18B is a rear perspective view of the two-piece foam headband of FIG. 18A once installed on a shield and assembled into a closed state suitable to span around a user's head.

FIG. 18C is a rear perspective view of the headband and shield of FIG. 18B after optional cut-out of a central section of a front piece of the originally two-piece headband to enable improved airflow within the interior of the shield.

DETAILED DESCRIPTION

The figures of the illustrated embodiments show a face and head shield 10 composed of a singular unitary piece of transparent polymeric material formed into a three-dimensional non-spherical dome or shell that bounds three out of four sides of a hollow interior space within this dome or shell. At a fourth side of the dome or shell (referred to herein as a rear side), a boundary edge of the dome or shell delimits an opening through which a user's face is received into the interior space of the dome or shell in order to don the face and head shield in a working position. Once donned in such position, the shield protects both the entire facial region of the user's head, and a substantial cranial region thereof, from physical contact with potential hazards, for example droplet or aerosol carried contagions emitted by a coughing, sneezing or otherwise contagion-emitting patient under the medical care of the user. The same face shield may of course also be used for other protective applications.

In the first and second embodiments example, the boundary edge of the dome or shell resides in a singular flat plane, for example as would be seen if the dome or shell were placed boundary edge down atop a flat tabletop. This plane is used as a reference plane governing directions in which height and width dimensions H, W of the shield are measured orthogonally of one another. A third depth dimension D of the shield is measured in a third direction residing normal to this reference plane, and thus orthogonal to the height and width dimensions. The depth of the shield's interior space thus refers to measurement made perpendicularly from the plane of the shield's open rear side to an inner surface of the shield that resides oppositely of, and faces toward, said open rear side of the shield. The height and width of the shield are at their greatest in the aforementioned reference plane at the open rear side of the dome or shell. The height of the opening exceeds the width thereof, whereby the opening of the shield has an oblong shape having an elongated primary dimension and a shorter secondary dimension. As used herein, the top and bottom ends of the shield 12, 14 are those which are spaced apart by the longer primary dimension, while lateral sides 16, 18 of the shield are spaced apart by the smaller secondary dimension.

A rounded apex 20 of the shield's dome-like or shell-like shape, i.e. the area thereof at which the depth dimension D is at its greatest, resides nearer to the top end 12 of the shield 10 than to the opposing bottom end 14 thereof. From the rounded profile of the apex 20, the depth of the shield tapers toward the bottom end 14 of the shield, initially in a generally linear fashion for a majority of the distance from the apex 20 to the bottom end 14, before curving downward more aggressively just before the bottom end 14 in order to impart a rounded shape, rather than a sharp point, to the shield's bottom end. Likewise, the top end 12 of the shield is also slightly rounded in side-view profile, though at a relatively steep slope from the nearby apex 20. The depth of the shield is also curved in its end-view profile, in which both the apex 20 and the depth-tapered lower portion therebelow have a subtle curvature over a central majority of the shield's width, before the depth drops off more aggressively near the two lateral sides 16, 18. The relatively flat, but subtly curved central region of the shield's width spans across the user's face in the worn position of the shield, from which the more sharply curved side-adjacent regions of the shield will then turn posteriorly (rearwardly) of the user's face to cover at least the cheeks and temples of the user, and possibly also an entirety or partial fraction of the user's ears.

The forgoing shape of the shield 10 is symmetric in the width direction, i.e.

symmetric across a longitudinal midplane running in the height direction in orthogonal relation to the reference plane. On the other hand, the shield is asymmetric in the height direction, i.e. lacking symmetry across any transverse plane running in the width direction in orthogonal relation to the reference plane. By having a three-dimensional form that is of profiled shape in both end view (i.e. as viewed from either top or bottom end 12, 14) and side view (i.e. as viewed from either lateral side 16, 18), the shield is able to more comprehensively protect the user's head relative to the aforementioned conventional shields.

This improved protective coverage of can be seen in FIGS. 3 and 4 , where the shield is shown in a worn position on the user's head, from which it can be seen that the elongated primary dimension (height H) of the shield's rear opening is large enough to accommodate a chin-to-crown measurement of the user's head in an superior-inferior (top to bottom) anatomical direction, and the shorter secondary dimension (width W) of the shield's rear opening accommodates a narrower width measurement of the user's head in a lateral anatomical direction (side to side). A substantial portion of the user's head, including the entire face thereof, is thus safely protected within the confines of the dome-like or shell-like structure of the shield 10.

In the first illustrated embodiment, the shield 10 is supported on the user's head by a headband style support frame 30 that is worn circumferentially around the user's head at forehead level. It will be appreciated that other known styles of support frame may alternatively be employed, for example using an eyewear-style support frame that is borne on the user's ears and bridge of the nose. In the headband example of the first illustrated embodiment, a front segment 32 of the headband that spans across the user's forehead features a set of one of more coupling elements 34A thereof, of which there are two in the illustrated example. Each coupling element 34A is shown carried at a forwardly protruding mounting area 36 of the front segment 32 that resides adjacent a respective lateral end of the front segment. Each mounting area 36 juts forwardly from a remainder of the segment 32 that fits in generally flush conforming fashion against the user's forehead. The protruding mounting area(s) are used to set the shield in anteriorly (forwardly) spaced relation to the user's face when worn, as shown in the figures, to allow airflow between the user's face and the shield. In the illustrated example, each coupling element 34A is a piece of hook or loop fastener.

A matching set of corresponding coupling elements 34B are provided on the shield at the inner surface thereof, and at an elevation at or near the apex 20, thus closer to the top end 12 of the shield than to the bottom end 14 thereof. In the illustrated example with two coupling elements per set, the spacing between the support frame's coupling elements 34A matches that between the shield's corresponding coupling elements 34B, of which the latter are situated at opposite ends of the shield's central region so as to reside near, but inward from, the lateral sides 14, 16 of the shield. Accordingly, elements 34B align with the support frame's coupling elements 34A that are worn at or near opposite ends of the user's forehead, thus residing near, but inward from, the user's temples. In the illustrated example, each of the shield's coupling elements 34B is a piece of hook or loop fastener matable with the respective hook or loop fastener 34A of the support frame 30. The illustrated embodiment thus represents a scenario in which the shield is removably attachable to the support frame 30, whereby the support frame may be worn on an ongoing basis, and repeatedly re-used, while the shield is instead intermittently swapped out for a replacement shield after each use (e.g. after each patient, in medical applications). Such replacement may be performed on a single-use disposable basis, where the worn shield is destroyed after use, rather than sterilized and re-used. It will be appreciated that releasable couplers other than hook and loop fasteners may be employed. In other embodiments, couplers capable of repeated attachment and detachment need not necessarily be used, for example in instances where the head frame is also treated as a one-time-use disposable product that is discarded together with the used shield.

As shown in FIGS. 3 and 4 , when the shield is worn, the reference plane containing the open rear side of the shield 10 lies at an oblique incline relative to the anatomical planes of the user's body. This oblique plane cuts through the user's head in a posterior-anterior (back to front) and superior-inferior (top to bottom) direction from a location situated superior to (above) the crown of the user's head, to a location situated inferior to (below) the user's chin and anterior to (in front of) the user's neck. With the open rear side of the shield 10 in this oblique plane, the apex 20 of the shield resides anteriorly of the user's forehead, from which the depth-tapered lower portion of the shield hangs downwardly over the user's face. The portion of the shield spanning from the forehead-level apex 20 to the bottom end 14 of the shield's rear opening is thus referred to herein as the lower facial portion 44, since it cover's the facial areas of the wearer, while the portion of the shield spanning from the forehead-level apex 20 to the top end 12 of the shield's rear opening is referred to as the upper cranial portion 46, since it spans posteriorly over the user's cranium. In this worn position of the shield, the entire face of the user's head thus resides within the protected interior space of the shield, as does a substantial cranial region of the user's head, including at least the forehead, temples, and frontal scalp, and preferably also including the mid-scalp, and optimally also at least part of the crown of the user's head. The coverage may also include all or parts of the user's ears. So unlike conventional shields that employ a profiled shape only in the horizontal width direction to curve around to the sides of the face, the novel dome-like or shell-like shape of the inventive shield also curves upwardly over the forehead and spans rearwardly over the scalp. The shield thus avoids susceptibility to falling droplets or aerosol particles from above, and also protects against accumulation of such contaminants in the user's hair, which can present a risk for later infection.

As shown in FIGS. 5 and 6 , the shield can be easily and affordably manufactured by application of a thermal forming or vacuum forming process applied to a form that has been fabricated according to the intended size and shape of the shield, though other manufacturing techniques may alternatively be employed. FIG. 5 shows the platform P of a vacuum former atop which such a form F has been placed, over which a sheet of transparent plastic is placeable for heating and vacuum forming over the form F to impart the shield's three-dimensional dome or shell shape to the heated plastic. FIG. 6 shows the vacuum formed plastic once cooled and removed from the form, at which point an outer peripheral margin M of the plastic sheet projects outwardly from around the boundary edge of the dome or shell's opening, before this margin M is trimmed off, or trimmed down, to leave behind the final shape of the finished shield. As shown in the embodiments of FIGS. 12, 14 , for even further comprehensive coverage of the user's head and neck, the shield may optionally include an out-turned flange 112 at the boundary edge around the rear opening of the shield, whether spanning an entirety or partial fraction of the opening's circumference. By way of this flange, an additional flexible bib or shroud may optionally be attached to cover any exposed parts of the user's neck, shoulders, upper chest, and/or back of the head that are not covered by the shield and whatever garment is worn on the user's upper torso. However, it will also be appreciated that particular inclusion of a flange is not be essential to such optional attachment of a bib or shroud at the perimeter of the shield's rear opening, as such accessory may instead be adhered directly to the domed surface of the shield, rather than a supplementary flange projecting outwardly therefrom around the rear opening.

FIG. 7 illustrates such optional attachment of a front bib 38 to the shield over only a lower portion of the rear opening's circumference, whereby this front bib hangs anteriorly of the user's neck and upper chest to provide additional protection thereto, which otherwise may be left unprotected above the neckline of the user's upper torso garment. As an alternative to the FIG. 7 bib that spans only a partial circumference of the rear opening of the shield, FIG. 8 illustrates a larger shroud 38′ that spans the entire circumference of the shield's rear opening, so as to provide fully comprehensive coverage of the back of the user's head, along with the front, rear and sides of the user's neck, and also the shoulders and upper chest.

In addition to the front bib and shroud, FIGS. 7 and 8 also illustrate a two-piece assembly of the headband style support frame 30′, where the front segment 32 of the headband is composed of a foam piece, and a remainder of the headband is composed of a flexible strap 39 of preferably elastic material that is resiliently stretchable in a longitudinal direction of the strap. The foam piece of the front segment 32 has a foam base strip that abuts generally flush against the user's forehead, and a pair of smaller foam blocks attached to a front side of the base strip to define the protruding mounting areas 36 so that the shield stands off from the user's face in the worn position to maintain the air space between the user's face and the shield. Longitudinally opposing ends of the strap 39 are attached to the two opposing ends of the foam base strip of the front segment piece 32 to collectively form the overall headband 30′.

FIG. 9 illustrates a second embodiment of the head and face shield 10′ that can be used to omit the need for a full-circumference headband 30, 30′ with protruding mounting features 36 on its front segment 32. In this embodiment, the shield 10′ features a pair of inward protrusions 40A, 40B formed as seamlessly integral features of the dome or shell. These protrusions project inwardly from the inner surface of the dome or shell at the central region thereof, and at an elevation of that region at or near where the apex 20 and the tapered lower portion of the dome or shell join together. This way, the protrusions 40A, 40B reside at an elevation generally equal to the user's forehead in the worn position of the shield 10′. As an integral part of the dome or shell, the protrusions 40A, 40B at the inner surface of the shield 10′ each coincide with a respective matching depression 42A, 42B in the opposing outer surface of the shield that faces away from the user's face in the shield's worn position. The two protrusions 40A, 40B are spaced apart from one another, in the same cross-wise direction in which the width W of the rear opening is measured, by a suitable distance d such that these protrusions are placed adjacent opposite ends of the user's forehead, but inward from the user's temples. In one example, this distance d between the protrusions 40A, 40B measured between five and six inches, inclusive.

The protruding distance of the two protrusions 40A, 40B measured from immediately surrounding areas of the shield's inner surface, or the corresponding recessed depth of the depressions 42A, 42B measured from immediately surrounding areas of the shield's outer surface, may be between 1 and 2 inches, and more particularly between 1.25 and 1.75 inches in some embodiments, for example measuring 1.5 inches in one particular non-limiting example. A protrusion axis A on which each protrusion 40A, 40B juts into the interior space of the shield may be at a slightly oblique downward angle relative to the slope at which an upper portion 46 of the shield spans between the top end 12 of the shield and the rounded apex 20. In the worn position of the shield, where the upper portion 46 thereof spans posteriorly from the top of the forehead over the scalp in a generally horizontal orientation, the protrusion axes A are thus angled at a slightly downward slope toward the user's forehead, though at a lesser downward slope than the angle of the shield's depth dimension D, which is perpendicular to the plane of the shield's rear opening.

For optimal comfort and/or gripping effect, a pad 48 of foam or other cushioning, grippy or sweat-absorbent material of distinct composition from that of the polymeric shield may be adhered to the terminal end of each protrusion 40A, 40B inside the interior space of the shield's dome or shell shape. In the worn position of the shield 10′, these terminal ends of the inward protrusions 40A, 40B abut against the user's forehead, whether directly, or indirectly through the optional pads 48. The protrusions thus serve as stand-offs for the purpose of maintaining the shield 10 in anteriorly (forwardly) spaced relation from the user's face in order to create an open air space therebetween for the comfort of the user. Incorporating these stand-offs directly into the shield itself simplifies the manufacture of the overall apparatus by which the shield is supported on the wearer, as the front headband segment 32 of the earlier embodiment can be omitted altogether, having been replaced by integrally formed features of the shield itself. As shown in FIGS. 9A and 9C, the same flexible, preferably elastic strap 39 previously used with the foam-piece front segment 32 of the earlier headband embodiment is instead coupled directly to the shield 10′ itself at the lateral sides 16, 18 thereof near the perimeter of the rear opening, and at matching or similar elevation to the protrusions 40A, 40B.

For the purpose of such connection between the shield and the strap 39, the coupling elements 34B used in the earlier embodiment to attach the central region of the shield's inner surface to the front segment of the two-piece headband 30′ may instead be relocated to the lateral sides 16, 18 of the shield for coupling with corresponding coupling elements on the flexible elastic strap 50 at or near the longitudinally opposing ends thereof. However, instead of the hook and loop fastener elements, any other coupling means capable of enabling attachment between the shield 10′ and the strap 39 may alternatively be used via cooperating features on these two components. In one alternative example, the ends of the straps may be fed through small slits in the sides of the shield 10′, so that the shield is frictionally held on the strap. Or a pair of holes may be provided in the sides of the shield for snap fit mating with male coupler features on the strap 39.

It will be appreciated that the same integral incorporation of stand-off protrusions into the shield itself may be used on shields of more conventional shape, and not just on the novel dome or shell-like shape of the inventive shield whose inner user-facing side is concavely shaped in both of the orthogonal height and width dimensions of the shield. It will also be appreciated that while the illustrated example employs two small protrusions 40A, 40B at laterally spaced locations across the inside of the shield, another embodiment could alternatively a singular wider protrusion that spans more of the shield's width to achieve sufficient contact area with the forehead to also maintain a consistent and uniform air space between the shield and the user's face. It will also be appreciated that in the illustrated vacuum formed example, the inward protrusions on the inner side of the shield are coexistent with matching recessed depressions at the outer side of the shield, it will be appreciated that these need not be case in the instance of other manufacturing technics (plastic molding, 3D printing, etc.), where protrusions one side need necessary coincide with depressions on the other.

A third embodiment of the head and face shield 10″ is shown in FIGS. 10 and 11 . The shield 10″ once again features a dome-like or shell-like shape having a singular open side at the rear thereof through which the user's head is received into the interior space of the shield when donned, and once again features two inward protrusions 40A′, 40B′ jutting from the inner surface of the shield at forehead level at or near the apex 20, though in this example these protrusions and the matching depression 42A′, 42B′ in the opposing outer surface of the shield are larger than in the earlier embodiment of FIG. 9 , thus increasing the surface area of the terminal end of each protrusion.

In this embodiment, the shield may be supported by a full-circumference headband that spans around the wearer's entire head, with the front segment of the headband being adhesively bonded (e.g. with double sided tape) or otherwise fastened (e.g. via hook and loop fastener) to the terminal ends of the protrusions 40A′, 40B′. To guide proper alignment between the headband and the shield 10″, the illustrated example of the shield features a vertical alignment marker 43A lying upright on each side 16, 18 of the shield just outside the respective depression 42A′, 42B′ and a horizontal alignment marker 43B lying laterally across the terminal end of each protrusion 40A′, 40B′. In the illustrated embodiment, each marker 43A, 43B is an integrally formed narrow groove recessed in the exterior of the shield, thus coinciding with a protruding narrow rib on the interior of the shield.

The upper cranial portion 46 of the shield 10″ differs from that of the earlier embodiments in that instead of a smooth and continuous curvature in its side-to-side width profile (as viewed from the front or rear of the shield), its side-to-side profile instead has a corrugated central region. Here, two troughs 52A, 52B are recessed into the exterior of the shield on opposing sides of a singular airflow channel 54 of parallel relation to the two neighbouring troughs 52A, 52B. The troughs 52A, 52B and airflow channel 54 run longitudinally of the cranial portion 46 of the shield from the top end 12 of the shield's rear opening toward, but stopping short of, the apex 20 of the shield. A floor 56 of each trough defines a narrow strip-like seat for resting atop the wearer's scalp. A ceiling 58 of the airflow channel 54 is of elevated relation to the trough floors 56, as are the neighbouring areas 60 of the topside of the cranial portion 46 that reside outward of the two troughs 52A, 52B. Accordingly, when the trough floors 56 are seated atop the wearer's scalp, the channel ceiling 58 and neighbouring areas 60 are stood off from the wearer's scalp in spaced relation thereover. The troughs 52A, 52B and the airflow channel 54 are seamlessly integral parts of the preferably vacuum-formed (though optionally molded, or 3D-printed) shape of the shield itself.

The end of the airflow channel 54 that intersects the rear opening of the shield at the top end 12 thereof, and thus residing distally of the shield's lower facial portion 44, is referred to an as inlet end 54A of the channel 54, as it is this end through which airflow in induced through the airflow channel 54 during use of the shield. An inlet fitting 62 of materially distinct and separate construction from the shield itself is installed in the airflow channel 54 at the inlet end thereof, for example being adhesively bonded to the transparent polymeric material of the shield at the ceiling 58 and/or sidewalls of the airflow channel 54 by one or more pieces of double sided tape 64 (FIG. 11A), though other suitable adhesives compatible with the shield material may alternatively be employed. The inlet fitting 62 has a cross-sectional shape of matching outer profile to the airflow channel 54 so as to fully occupy and close off the inlet end thereof, except for an internal through-bore 62A of the fitting through which air is admissible to the airflow channel 54 from an outside source, as described in more detail below.

A channel cover 64 is also defined separately of the shield itself, at least in the illustrated embodiment where the shield 10″ is vacuum formed. The channel cover 64 may be of the same material of the shield, or of distinct material composition therefrom. In the illustrated embodiment, the channel cover 64 is also adhesively bonded to the polymeric material of the shield, but at the undersides of the trough floors 56, for example using two elongated strips of double sided tape 66 each running along a respective perimeter of the channel cover 64. The channel cover 64 has an elongated strip-like shape spanning a nearly full length of the airflow channel 54, starting from the inlet end 54A or inlet fitting 62 thereof, but stopping short of an opposing outlet end 54B thereof (FIG. 11C). This outlet end 54B resides near the apex 20 of the shield, and thus proximally of the lower facial portion 44 of the shield that is joined to the channel-equipped upper cranial portion by said apex 20. The outlet end 54B of the airflow channel 54 is left uncovered by the channel cover 64, which otherwise closes off the bottom of the airflow channel over the full length thereof between the inlet and outlet ends 54A, 54B, or at least over a substantially full length thereof from the inlet fitting 62 to the outlet end 54B if the channel cover does not span fully across the underside of the inlet fitting 62 right to the terminus of the channel's inlet end 54A. With the cover 64 installed, the originally open-bottomed airway channel 54 is now an enclosed channel bound on all four sides thereof.

The purpose of the airflow channel is illustrated in FIG. 11C, where an air supply conduit 68, typically comprised of one of more sections of flexible hose, has an output end thereof coupled to the inlet fitting 62 of the finished airflow channel 54. An opposing supply end of the air supply conduit 68 is coupled to a forced air source 69, such as a portable, battery-operated fan carried somewhere on the user's person. Forced air from the fan 69 is routed through the conduit 68 into the airflow channel 54 of the finished shield 10″ via the installed inlet fitting 62 thereof. The air flows longitudinally through the airflow channel 54 to the outlet end 54B thereof, where the air is blown downwardly along in the inner surface of the shield apex 20 to the lower facial portion 44 of the shield, thus feeding into the space between the wearer's face and the lower facial portion 44 of the shield. Such airflow is useful to prevent or limit condensation buildup/fogging of the shield, and to help cool the user's skin. Alternatively, the fan may be accompanied a heater to blow warm air for use of the shield in cold environments.

FIG. 11D shows the shield 10″ of FIG. 10C in combination with a shroud 38″ attached around the full circumference of the shield's rear opening. The shroud 38″ in this case is equipped with a conduit port 70 by which the air supply conduit 68 can be routed from the inlet fitting 62 of the shield's airflow channel 54 to the forced air source 69. In the illustrated example, the port 70 is a pass-through port having a flexible gasket 70A that seals externally around a flexible hose section of the air supply conduit 68. Alternatively, the port 70 may be a connection port to which two different sections of a multi-section air supply conduit may connected inside and outside the shroud to make respective connections to the forced air source 69 and the channel-equipped shield 10″. Either way, the channel-equipped shield 10″ can be connected to a portable forced air source 69 worn on the user's person somewhere beneath the user's shroud, but without sacrificing the effective germ barrier provided by the protective shield 10″ and attached shroud 38″.

FIG. 12 shows a variant 10′″ of the head and face shield of FIG. 10 . The variant shield 10′″ once again features integrally formed inward protrusions and matching external depressions 42A′, 42B′ at a forehead-level elevation on the shield, and once again also features the externally recessed troughs 52A, 52B and central airflow channel 54 in the upper cranial portion 46 of the shield. As also illustrated in the FIG. 10 version, the two external depressions 42A′, 42B′ are separated from one another by an upright central brow ridge 80 that embodies the apex of the shield, and whose externally convex shape forms the gradually curved transition from the upper cranial portion 46 of the shield to the lower facial portion 44 of the shield. The overall area that resides at forehead level of the wearer and is occupied by the internal protrusions, coincident external depressions, and the upright brow ridge 80 therebetween, is therefore referred to herein as a transitional region, since it joins together the downwardly hanging facial portion of the shield that covers the wearer's face and the rearwardly extending cranial portion that overlies the top of the wearer's head.

The variant of FIG. 12 differs from the FIG. 10 shield in that the lower facial portion 44′, instead of being a smoothly continuous extension of the brow ridge 80, is bumped forwardly outward therefrom, whereby the lower facial portion 44′ of this variant 10′″ is spaced further from the plane of the shield's open rear than in the FIG. 10 shield. The variant shield 10′″ of FIG. 12 thus possesses a greater depth at the lower facial portion 44′ than in the earlier FIG. 10 shield. In the worn position of the shield, the lower facial portion 44′ thus resides further forward (anteriorly) of the user's face than the earlier FIG. 10 shield, which leaves more space between the user's face and the shield at elevations below the forehead-level depressions 42A′, 42B′. This modified shape and increased depth of the shield at the lower facial portion 44′ thereof better accommodates wearing of facially protruding equipment (magnification loupes, surgical/dental headlight, etc.) behind the shield. For example, this variant of the shield may be particularly beneficial to dental and surgical practitioners who often require such equipment, typically worn on an eyewear frame. A light-equipped and/or loupe-equipped eyewear frame could thus be worn under the shield of FIG. 12 .

The bumped-out position of the lower facial portion 44′ relative to the overlying transitional apex or brow ridge 80 of the shield creates a broad external ledge 84 that spans across an entirety, or substantial entirety, of the width of the shield. This external ledge 84 resides at an elevation that is shared by the bottom walls of the two inward protrusions found on the interior of the shield. The topsides of these bottom walls of the inward protrusions define bottom floors 86 of the two matching depressions 42A, 42B in the exterior of the shield. The external ledge 84 is thus composed of these floors 86 of the two depressions, plus a shallower joining strip 88 that spans across the front of the brow ridge 80 and joins together the two depression floors 86. The external ledge 84 juts forwardly from the two depressions 42A′, 42B′ and the central brow ridge 80, and thus in the worn position of the shield, juts anteriorly outward from the wearer's face at a lower area of the forehead just over the user's eyes (e.g. at approximately eyebrow level). While the increased shield depth crated by the bumped-out shape of the lower facial portion 44′ allows loupes or a headlight to be worn under the shield, as described above, the external ledge 84 also creates an exposed external support surface that is uncovered by any other features lying overhead thereof, and on which loupes, a headlight or other accessories may optionally be mounted externally to the shield itself, instead of being worn beneath the shield.

This is schematically illustrated in FIG. 12C, where a surgical or dental headlight 90 is mountable in secured fashion atop the external ledge 84. In the illustrated example, securing the headlight accessory 90 is attained by co-operable mating of a first piece of hook or loop fastener material 90 that is adhered or adherable to the underside of a support base of the headlight 90, and a corresponding second piece of loop or hook fastener material 92 that is adhered or adherable on top of the external ledge 84 of the shield. Other fasteners, e.g.

double-sided adhesive tape, may alternatively be employed for such mounting of a component to the external ledge 84, provided that the bonding or coupling strength thereof is sufficient to hold the accessory.

While the variant in FIG. 12 features a broad external ledge that spans an entire or substantially entire width of the shield, thus enabling fastened connection to the external ledge 84 at the center joining strip 88 thereof for optimal central placement of a headlight or other typically-centered accessory, it will be appreciated that the floors 86 of the two external depressions 42A′, 42B′ in the earlier shield of FIG. 10 may similarly be employed as support surfaces to which one or more accessories may be mounted externally to the shield. This may be a singular accessory, with a U-shaped or suitably shaped base capable of placement atop the two depression floors 86 in embracing relation about the front of the brow ridge 80, or two separate accessories, each mounted to the floor 86 of a respective one of the two depressions 42A′, 42B′.

FIGS. 13A through 13C illustrate a variant of the airflow channel componentry shown earlier in FIGS. 11A through 11D. In the variant of FIG. 13 , the air inlet fitting 62′ for receiving the output end of the air supply conduit 68 is not adhesively bonded to the shield as describe previously. Instead, the inlet fitting 62′ is clipped to the shield over the boundary edge of the shield's rear opening using a connector clip 94 that is attached to a topside of the inlet fitting 62′. The clip 94 is attached to the inlet fitting 62′ at or near a rear end 62B thereof that remains outside the airflow channel 54 of the shield when the inlet fitting 62′ has been clipped thereto. Though the illustrated example shows the entirety of the inlet fitting 62′ residing outside the airflow channel 54 at the inlet end thereof, it will be appreciated that at least part of the inlet fitting 62′ may reside inside airflow channel 54 and conform to the cross-sectional shape thereof, as described earlier with reference to FIG. 11 .

Another difference in the FIG. 13 variant is that the channel cover 64′ of this variant is attached to the inlet fitting 62′, as is therefore at least partially supported thereby, rather than being separately attached to the shield independently of the inlet fitting. Accordingly, the inlet fitting 62′ and channel cover 64′ can be quickly and conveniently attached to the shield through a singular clipped connection. That being said, additional adhesion of the channel cover 64′ to the shield may also be employed to best ensure that it is securely held in its intended position closing off the bottom of the airflow channel 54. The channel cover 64′ is cantilevered from the inlet fitting 62′ at a front end 62C thereof that is opposite to the rear end 62B at which the output end of the air supply conduit 68 is connectable. Another difference in this variant is that the channel cover 64′ has a two-piece construction, rather than the one-piece construction shown in FIG. 11 . Of the two pieces in the FIG. 13 variant, one piece is a stationary cover component 96, and the other piece is a movable adjustment component 98.

The stationary cover component 96 is an elongated component that serves the same purpose as the one-piece channel cover 64 of FIG. 11 , i.e. to form a floor or bottom wall of the shield's airflow channel 54 when installed on the shield. However, in the FIG. 13 variant, the stationary cover component 96 has a series of vent openings 100A therein that are spaced apart from one another along the elongated length dimension of the piece, whereby these vent openings 100A are longitudinally distributed along the floor or bottom wall of the airflow channel 54 when the channel cover 64′ is installed on the shield. The movable adjustment component 98 is also an elongated component having a matching series of vent openings 100B therein that are spaced apart from one another along the elongated length dimension of the piece. The quantity of vent openings in the two components 96, 98 are equal, as is the spacing between the vent openings in each component. The movable adjustment component 98 is slidably mated with the stationary cover component so as to be slidable back and forth thereon in the longitudinal/lengthwise direction thereof, as schematically shown by arrow 102 in FIG. 13A. The movable adjustment component 98 is thereby movable relative to the stationary cover component 96 to control the degree to which the vent openings 100A of the stationary cover component are covered or open.

In a fully open position of the movable adjustment component 98, all of the vent openings 100A in the stationary cover component 96 are fully aligned with the matching vent openings 100B in the movable adjustment component 98, whereby the crown and/or scalp of the user's head are exposed to the airflow through the airflow channel 54. This can be used help cool the user, or alternatively to warm the user if the shield is being worn in a cold environment and the fan 69 is accompanied by a heater to increase the temperature of the force airflow through the channel 54. In a fully closed position of the movable adjustment component 98, each of the vent openings 100A in the stationary cover component 96 is unaligned with the matching vent opening 100B in the movable adjustment component 98. Instead, the vent openings 100A of the stationary cover component 96 are fully covered by solid areas of the movable adjustment component 98, i.e. closed areas that are materially intact between the vent openings 100B thereof. The movable adjustment component 98 may also be moved into intermediate positions in which the vent openings 100A of the stationary cover component 96 partially overlap with the vent openings 100B of the movable adjustment component 98, thereby achieving a partially open state of the two-piece channel cover 64′.

In the illustrated embodiment, both channel cover components 96, 98 are channel-shaped, thus having a pair of upright sidewalls 104A, 104B with a central bottom wall 106A, 106B spanning therebetween. The vent openings 100A, 100B of each component 96, 98 reside in the bottom wall 106A, 106B thereof, and the movable adjustment component 98 fits externally over the stationary cover component 96 at the underside thereof. Accordingly, the bottom wall 106B of the movable adjustment component 98 underlies the bottom wall 106A of the stationary cover component 98, and the sidewalls 104B of the movable adjustment component 98 neighbour the sidewalls 104A of the stationary cover component 96 at the exterior sides thereof. In the installed position of the airflow channel cover 64′, the sidewalls 104A, 104B of both channel cover components 96, 98 reside inside the airflow channel 54 of the shield, and run along the interior of the two sidewalls of the airflow channel 54. At the front end 62C of the inlet fitting 62′, the interior through-bore 62A thereof opens into the space between the two sidewalls 104A of the stationary cover component 96, as shown in FIG. 13C.

To maintain the slidably coupled relationship between the two components 96, 98, mating longitudinal ribs and slots may be provided on the interior of the movable adjustment component's sidewalls 104B and the exterior of the stationary cover components sidewalls 104A. It will be appreciated that the movable adjustment component 98 need not necessarily be a channel shaped component residing externally and beneath a slightly narrower channel-shaped stationary cover component 96. For example, the movable adjustment component 98 may instead ride atop the bottom wall 106A of the stationary cover component in the space between the sidewalls 104A thereof, provided that some part of the movable component 98 is accessible from outside the stationary cover component 96 to enable manipulation of the movable component's position along the stationary component.

The clip 94 of the inlet fitting 62′ is shown as an integrally attached clip, e.g. part of a plastic molded or 3D printed inlet fitting, though other means of attachment between the clip 94 and the body of the inlet fitting 62′ may alternatively be employed. The clip 94 has an elongated arm spanning forwardly from its attachment to the body of the inlet fitting 62′, and reaching past the front end 62C thereof in overhanging relation thereto. The clip arm has a terminal end tab 108 at its free end, a bottom tip 108A of which represents a lowermost point of the clip 94 in a normal default position thereof. Over at least a partial length of the overhanding portion of the clip arm that spans from the front end 62C of the inlet fitting 62′ to the terminal end tab 108, a series of tooth-like serrations 110 are provided on the underside of the clip arm. In a default position of the clip 94, the bottom tip 108A of the terminal end tab 108 resides at a lower elevation than a reference plane occupied by the top ends of the stationary sidewalls 104A of the air channel cover 64′. To install the inlet fitting 62′ and attached airflow channel cover 64′, the clip 94 is temporarily flexed upwardly from its default position, and the boundary edge of the shield's rear opening, and more specifically the portion of this boundary edge denoting the inlet end of the airflow channel 54, is slipped between the temporarily opened space between the reference plane and lifted clip. Once the inlet end of the airflow channel abuts the front end 62A of the inlet fitting, the clip 94 is released from its raised position, whereupon it will resiliently flex back downwardly toward its default position. This return of the clip 94 biases the bottom tip 108A of the end tab 108 down against the ceiling of the airflow channel 54, and likewise forces the serrations 110 down against the boundary edge of the airflow channel's inlet end, thus clamping the inlet fitting 62′ and attached channel cover 64′ in place in operable relation to the airflow channel. It will be appreciated that the particular design of the clip 94 and the particular area of the shield engaged thereby at or near the inlet end of the airflow channel 54 may vary from this particular example.

With reference to FIG. 12E, the rear perspective view of the shield 10′″ shows the inclusion of the out-turned flange 112, which in the illustrated example spans around the entirety of the boundary edge around the shield's rear opening. In such embodiments with the airflow channel 54, it be seen that the out-turned flange may protrude further outward from the rear opening at areas immediately neighbouring the airflow channel 54 on either side thereof.

In the illustrated example, the protruding depth of the flange 112 increases gradually over these channel-neighbouring areas in a centrally inward direction toward the airflow channel 54. As a result, this variable-depth section of the flange 112A forms a triangular gusset that serves to reinforce the shape of the airflow channel at the inlet end thereof.

Turning from FIG. 12E to FIGS. 14A through 14E, illustrated therein is a flexible attachment clip 114 having an extruded profile that is generally J-shaped in profile, as best shown in the isolated views of the flexible attachment clip 114 in FIGS. 14B-14E. This J-shaped profile includes a lower overbent hooking portion 116 denoting the curved bottom end of the J-shape, and a stem 118 standing upright from the hooking portion 116 to the define the top end of the J-shape. An originating bottom span 116A of the overbent hooking portions 116 juts outwardly to one side of the stem 118 from a bottom base end thereof. A returning top span 116B of the overbent hooking portion 116 is bends backward over the originating bottom span 116A, thus reaching back toward the stem 118. The returning top span 116 stops short of the stem 118 so as to leave a small gap space 120 between the stem 118 at a terminal end 116C of the returning top span 116B. FIGS. 14B and 14C illustrate one version of the J-shaped profile, where after the 180-degree curve at the hooking portion's distal bend 116D furthest from the stem 118, the remainder of the returning portion 116B is generally linear in its reach back toward the stem, and lies generally parallel to the similarly linear originating bottom span 116A. FIGS. 14D and 14E illustrate an alternate variant of the J-shaped profile, where the returning upper span 116B is curved throughout, and thus curves downwardly toward the originating bottom span 116A during its inward return toward the stem 118, rather than running parallel to the originating bottom span 116A.

The overbent hooking portion 116 is resiliently flexible, which allows the returning upper span 116B to be temporarily flexed away from the originating lower span 116A such that the out-turned flange 112 of the shield 10′″ can be inserted between the two spans 116A, 116B of the overbent hooking portion 16 via the small gap 120 left between the stem 118 and the terminal end 116C of the overbent hooking portion 116. The returning upper span 116B will snap back into its default position closely adjacent the originating bottom span 116A, thus biasing itself against the front side of the shield's out-turned flange 112, thereby holding the flexible connector clip 114 on the shield 10′″. In this installed position of the connector clip 114 on the shield 10′″, the stem 118 of the connector clip's J-shaped profile reaches into the interior space of the shield 10′″ through the rear opening thereof, and lines the interior surface of the shield along a perimeter strip thereof around the rear opening of the shield, as shown in FIG. 14A.

The flexible connector clip, for example composed of a flexible polymeric material, is flexible in its elongated extrusion direction, allowing it to conform to the interior contours of the shield at this interior perimeter strip around the rear opening of the shield. In the illustrated example, the extruded length of the flexible connector clip 114 spans a majority of the perimeter distance around the rear opening, preferably spanning all perimeter areas thereof, except for the inlet end of the airflow channel and the neighbouring areas occupied by the gusset-shaped portions 112A of the out-turned flange 112. In embodiments lacking the airflow channel 54, the flexible connector clip 114 may span the entire perimeter of the shield's rear opening.

In either case, the flexible connector clip may be used to attach a shroud to the shield. For such purposes, an exposed outer side 118A of stem 118 (the side opposite the overbent hooking portion 116) is equipped with a deposit of hook or loop fastener material 122, whether a continuous strip thereof spanning the full extruded length of the flexible connector clip, or discrete pieces of fastener material attached at spaced apart locations therealong. The shroud is equipped with a mating deposit of loop or hook fastener material around the head opening of the shroud. Accordingly, fastening together of hook and loop material on the shroud and the flexible connector clip 114 is operable to secure the shroud to the shield. Inside the shield 10′″, additional hook or loop fastener material may be applied across the bottom of the airflow channel cover 64, 64′, and on the neighbouring internal areas of the shield on either side of the airflow channel, in order to also mate with the loop or hook fastener material on the shroud, thereby achieving fastened connection of the shroud around the entire rear opening of the shield. Double sided tape or snap fasteners may alternatively be used in place of the hook and loop fastener to similarly enable convenient quick assembly by a customer or end-user from initially separate components. Alternatively, the shroud and the flexible connector clip 114 may instead be combined into a singular unit by a manufacturer or supplier, for example where the shroud is pre-sewn, pre-bonded with suitable adhesive, or even heat sealed to the stem of the flexible connector clip 114. A shorter flexible clip occupying only a lower half of the shield's perimeter edge may be similarly used to attach a front bib to the shield, instead of a full-circumference shroud.

Rather than rely solely on the gripping action of the overbent hooking portion 116 to hold the connector clip 114 on the shield 10′″, an additional deposit of hook or loop fastener material 124 may also be applied to the opposing inner side 118B of the stem 118 (i.e. the side facing the overbent hooking portion 116), again whether as a continuous strip or discrete pieces, for mating with mating deposit of loop or hook fastener applied to the interior surface of the shield 10′″ at the perimeter strip thereof neighbouring the rear opening. Alternatively, rather than hook and loop fastener, double sided tape may be used to adhesively bond the inner side 118B of the stem 118 of the flexible connector clip 114 to the opening-adjacent perimeter strip of the shield's interior. In yet another alternative, depending on the polymeric materials used for the flexible connector clip 114 and the shield, it may be possible to heat seal or sew these two components together, for example at the manufacturer or supplier level, instead of relying on customer or end-user assembly with hook and loop fastener or double-sided tape.

FIGS. 15A through 15C illustrate a fourth embodiment of the shield 10″″ that, like the second and third embodiments, once again features the inward protrusions 40A′, 20B′ and matching external depressions 42A′, 42B′ in the shield's transitional region at forehead level, and the airflow channel 54 and neighbouring troughs 52, 52B in the cranial portion 46 of the shield, and, as shown, may include the outer rim 112 from the third embodiment for optional use of the flexible attachment clip 114. The fourth embodiment differs however in different relative angles between particular features of the shield, and in the further inclusion of a pair of supportive downward protrusions 130A, 130B on the underside of the cranial portion, each of which corresponds with a matching recessed depression 132A, 132B in the topside of the cranial portion.

Each recessed depression 132A, 132B is an elongated channel-shaped depression residing in an anterior region of the cranial portion that resides nearest to the facial portion 44 of the shield. Each channel shaped depression 132A, 132B and coincident downward protrusion 130A, 130B lies longitudinally of the cranial portion 46 of the shield in parallel relation to the airflow channel 54, and is therefore of elongated shape in the front-to-back or anterior-posterior direction in which the cranial potion 46 spans from its connection to the facial portion 44. The illustrated example features two channel-shaped depression 132A, 132 and two coincident downward protrusion 130A, 130B, which are symmetrically disposed on opposite sides of the centrally located airflow channel 54 that resides a bisecting midplane that cuts symmetrically and vertically through the facial and cranial portions 44, 46 of the shield (as shown by line D-D of FIG. 15C). In the illustrated example, a front end of each channel-shaped depression 132A, 132 intersects with the top end of the respective forehead level depression 42A′, 42B′ on the respective side of the midplane at the transitional region of the shield.

The downward protrusions 130A, 130B each protrude downwardly surrounding areas of the underside of the cranial portion 46, to an even lower elevation than the floors of the troughs 52A, 52B. The bottom of each downward protrusion 130A, 130B thus denotes a lowermost surface of the cranial portion, the purpose of which is best seen in FIG. 16 , where the shield has been vertically cross-sectioned in a plane that is parallel to the midplane, but offset therefrom so as to cut centrally through one of the downward protrusions and its coincident topside depression. Here the bottom of this cross-sectioned protrusion 130B can be seen to rest on the top of the user's head at the frontal scalp and/or mid-scalp thereof. As a result, other than this contact between the bottom of each downward protrusion with the top of the user's head, the entirety of the cranial portion 46 of the shield is elevated off of the top of the user's head, to enable airflow between the user's head and the cranial portion 46 of the shield for better ventilation and cooling. As an alternative to integrally formed depressions/protrusions on the cranial portion of the shield, a small block or bar of foam or other material may alternative be attached to the underside of the cranial portion of the shield, for example by double sided tape or hook and loop fastener, for the same purpose of maintaining clearance space between the top of the user's head and the cranial portion of the shield for airflow purposes, as illustrated by inclusion of such a foam block in FIGS. 1 and 2 .

To also increase the available space for airflow at the top of the user's head for comfortable wear, the fourth embodiment differs from the earlier embodiments in the relative angle between the cranial portion 46 and the facial portion 44, as best shown in the cross-sectional profile of FIG. 15D, where shield has been vertically bisected at its midplane. The facial region 44 has a linear profile in this cross-sectional plane over a substantial majority thereof, starting from its top end where it hangs down from the curved brow ridge 80 of the shield's transitional region. In this embodiment, the angle of divergence A₁ between the linear slopes of the facial and cranial portions is greater than 90-degrees, preferably at least 95-degrees, and approximately 100-degrees in one exemplary scenario. In the earlier embodiments, the relative angle between the linear slope profiles of the facial and cranial portions was a right angle of 90-degrees. In the present embodiment with the greater angle of divergence A₁, the clearance space between the top of the user's head and the overlying cranial portion of the shield is greater, and increases toward the back of the user's head, allowing plenty of room for ventilation and user comfort. In the illustrated example, the facial region 44 only deviates from this linear profile at a curved lower chin region 134 that connects the linear majority of the facial portion 44 to the terminal bottom end 14 of the opening's boundary edge. In the illustrated example, the cranial portion 46 is linearly profiled over its entire span from the top end of the brow ridge 80 to the top end of the opening's boundary edge. In this example, the divergence angle A₁ is therefore uniform over an entirety of cranial portion 46 and a substantial majority, and near entirety, of the facial portion 44. Regardless of the degree of uniformity in the chosen divergence angle, at no point along either of the facial portion nor the cranial portion does the slope of the cranial portion toward the rear end thereof (i.e. toward the top end of the shield's rear opening) ever have a divergent relationship to the slope of the facial portion toward the bottom end thereof (i.e. toward the bottom end of the shield's rear opening).

Another unique angular relationship between features of the fourth embodiment is the angular relationship found between the linear majority of the facial portion 44 and a headband attachment surface found the terminal end of each inward protrusion 40A, 40B at the forehead level transition region, as measured in cross-sectional planes that are parallel to the bisecting midplane of the shield, but that are offset therefrom so as to cut vertically through the terminal end of either inward protrusions 40A, 40B. This is best shown in FIG. 15E, in which the shield has been cross-sectioned through inward protrusion 40B. In this example, the distal end of inwardly protrusion 40B has a top half 136A that lies generally parallel to the linear majority of the facial portion 44 of the shield, but also a distinctly oriented bottom half 136B that serves as the headband attachment surface to which the front segment of a headband is attachable by suitable coupling elements, such as double sided tape applied to the headband or to headband attachment surface, or matably co-operable pieces of hook and loop fastener respectively applied to each thereof. This headband attachment surface 136B is not parallel to the linear majority of the shield's facial portion 44, and instead is obliquely angled at a small angle thereto in downwardly convergent relationship therewith. In the second and third embodiments, the distal end of each inward protrusion 40A, 40B is parallel to the linear majority of the facial portion 44 in cross-sectional planes that cut through the inward protrusions in parallel relation to the midplane. As a result, in those earlier embodiments, attachment of the front segment of a headband to the distal ends of the inward protrusions would place the linear majority of the facial portion 44 in parallel relationship to the front of the headband. So presuming the front of the headband is vertically oriented in a worn position of the user's head, the linear majority of the facial region would likewise reside in a vertical orientation in the worn position of the shield. In testing, applicant found that such design tended to produce a glare in the sight line of the wearer.

Referring to FIG. 16 , where the non-parallel headband attachment surface 136B at the terminal end of the inward protrusion 40B is shown in a generally vertical orientation, as would be supported by the generally vertical front of a worn headband (not shown), the result of the downwardly convergent relationship between the headband attachment surface 136B and the majority of the facial portion 44 is that the facial portion 44 is tilted in a downwardly rearward fashion angling toward the chest of the user. Testing found that this tilting of the worn position of the shield was effective to move the aforementioned glare out of the wearer's normal sight line. In prototyping, the tilt angle A₂ between the headband attachment surface 136B and the linearly sloped major surface of the facial region was selected as 5-degrees, though this angle may varied, for example between 2-degrees and 10-degrees, or more particularly between 3-degrees and 8-degrees. As also shown by FIG. 16 , the relative tilt angle A₂ between the headband attachment surface 136B and the linearly sloped major surface of the facial region has compounding effect with the relative divergence angle A₂ between the cranial and facial portions in terms of the resulting angular tilt of the cranial portion 46 relative to the top of the wearer's head, whereby tilt angle A₂ serves to further increase the available clearance space for airflow between the top of the user's head and the cranial portion of the shield. So, if headband attachment surface is oriented vertically in the worn position, the angle of inclination of the cranial portion 46 relative to horizontal, in degrees, would be A1+A2−90. It will be appreciated in practice however the front of the headband, in practice, would likely not have a truly vertical orientation, and instead have a slight upwardly rearward (posterior) slant in the worn position, owing to a natural slope of the forehead, and so the illustrated position of FIG. 16 with the vertical orientation of headband attachment surface 136B likely represents an exaggeration of the actual tilt that would be seen in the worn position of the shield, but is nonetheless useful to illustrate the rearwardly inclined slope of the cranial portion, and downwardly inward tilt of the facial portion.

Another change in relative orientation of features in the fourth embodiment is in the relative orientation of the inner sidewalls 138 of the two forehead-level depressions 42A, 42B and coincident inward protrusions 40A, 40B at the transitional region of the shield, which also double as sidewalls of the upright brow ridge 80 that separate the two forehead-level depressions 42A, 42B. When the shield is worn, air can flow upwardly or downwardly over the wearer's forehead through the inside of the brow ridge 80 between the two external depressions 42A, 42B, i.e. through the open airflow space 140 (FIG. 15F) left between the two internal protrusions 40A, 40B. To help with exhaust of warm air and carbon dioxide from the facial area, bottom halves 138A of the sidewalls 138 are in non-parallel tilted relation to one another in an upwardly convergent and downwardly divergent fashion. As a result, the airflow space between the two inward protrusions 40A is wider at a lower end 140 thereof that coincides with the bottom ends of the inward protrusions, i.e. the floors of the external depressions 42A, 42B, that it is at a narrower mid-region situated further up this airflow space. Top halves 138B of the sidewalls 138 are also tilted relative to one another, but in opposing fashion to the lower halves, thus being upwardly divergent and downwardly convergent to one another. From its wider bottom end, the airflow space initially tapers to a narrower width to the mid-region of the airflow space, and then widens again toward an open, unobstructed top end of the airflow space, which resides coincident with the top ends of the inward protrusions 40A, 40B. Accordingly, the airflow space is configured with a constricted mid-region between two ends of greater with than said mid-region, with the intent of providing a chimney or venturi like effect for more effective drawing of heated/exhaled air upwardly out of the user's facial area for escape through the open clearance space between the cranial portion of the shield and the top of the user's head. Another differentiating feature of the fourth embodiment shield 10″″ is the inclusion of a respective stiffening ridge 142 integrally formed in each of the lateral sides of the shield in symmetrically matching positions each running longitudinally rearward from the floor of the respective forehead-level depression 42A, 42B in a coincident plane therewith to the boundary edge of the shield's rear opening. The headband attachment surface 136B stands upright from this plane, such that when the front segment of a headband is attached this surface 136B of the shield, the headband will run rearwardly from this attachment surface with a bottom edge of the headband in generally parallel relation to the stiffening ridge 142. The stiffening ridges thereby help retain the form and stability of the shield when worn.

FIG. 17 shows a one-piece adjustable foam headband 200 of the present invention, which is just one example of a type of headband that may be attached to any of the forgoing shields at the terminals ends of the forehead-level protrusions 40A, 40B, whether or not the attachment surfaces thereof to which the headband is attached is parallel or not to the facial portion 44 of the shield. The headband 200 is composed of a singular unitary strip of foam material having a length dimension LS in which said strip of foam material is elongated relative to the other two of its three orthogonal dimension, namely its width WS and its thickness TS. Of these three dimensions, the thickness TS is the smallest, the length LS is the greatest, and the width WS in intermediate of the two, and many times lesser than the length LS. The strip has two faces F1, F2 that that lie opposite of one another and between which the thickness TS is measured. The strip has first and second ends E1, E2 lying oppositely of one another, and between which the length dimension LS is measured. A fractional portion of the strip's length spanning from the first end E1 toward the second end E2 is configured as a barbed tail 202 that has matching sets of barbs 204 arranged in series along the length of the strip on the two sides of the strip that lie opposite one another across the width WS of the strip. Another fractional portion of the strip's length is a widened end region that resides adjacent the second end E2, and that has a greater width than the barbed tail. As shown, this widened end region 204 may constitute a majority of the strip, thus spanning a substantially full length from end E2 to the barbed tail, though preferably with a tapered transition rather than a squared shoulder where the two meet. The strip of foam is flexible and bendable in said longitudinal dimension, such that the first and second ends can be brought together to impart a curvature to the strip, and form the strip into a closed loop. The widened end region has one or more receiver openings therein, for example a pair of receiver slots 206 spaced apart in the length dimension. Each receiver opening has a width that is slightly less than the tip-to-tip width of the barbed tail at any pair of aligned barbs on its opposing sides.

The compressibility of the foam allows this tip-to-tip width of the barbed tail to be temporarily reduced, whereby the second end E2 of the strip and any number of the barb pairs can be forced through each of the receiver slots 206, whereafter the tip-to-tip width of the barbs forced through the slots 206 will return to its default width. At their full width, the barbs resist pulling of the barbed tail back through the slots. As shown in FIG. 17B, insertion of the barbed tail through one slot from one face of the strip to the other in a first direction, and subsequent passage of the barbed tail through the next slot in the reverse direction, is operable to secure the strip in a closed loop state. With the strip curled into such a loop, preferably the barbed tail is inserted inwardly through the first slot 206A nearest to the end E2 from the outer face of the strip that faces outwardly from the closed loop shape, and then fed back outwardly through the second slot 206B further from the end E2 and back to the outside the loop. To tighten the headband around one's head, the wearer can then simply grab the exposed first end E1 of the barbed tail outside the loop, and pull on it, to cinch the headband tighter.

To secure the headband 200 to the headband attachment surfaces 136B at the forehead level protrusions 40A, 40B of a shield, coupling elements 208 may be preinstalled on the outer face of the headband 200 at a mid-length, preferably full-width, area of the foam strip 210 that resides beyond the inner end of the barbed tail and will form the front section of the headband once installed on the shield, and/or installed on the headband attachment surfaces 136B of the shield. The illustrated example employs two pieces of double-sided tape 208 as the coupling elements, which are pre-attached to the foam strip of the headband at a lengthwise spacing from one another that matches the known distance between a shield's headband attachment surfaces. Each piece of tape includes a respective peel-away cover that is removed to reveal the tape come time for assembly of the headband onto a shield. In other examples, such double-sided tape may instead be applied to the headband attachment surfaces of the shield. In another example, hook fastener material may be applied to a first one of either the headband or the shield, and loop fastener material applied to the second one of either the headband or shield for cooperative mating of the hook and loop fastener materials when the time comes to secure the headband and shield together. FIGS. 17C and 17C show the one-piece, pull-tight adjustable headband installed in attached relation to the headband attachment surfaces of a shield.

FIG. 18A through 18C illustrate another headband 300 of the present invention, also constituted entirely of foam except for coupling elements used to connect different component, and also capable of adjusting the size of the closed-loop formed by the headband around the user's head, but employing a two-piece construction rather than the one-piece construction of FIG. 17 . This headband 300 features a first strip 300A of foam material having a first pair of opposing ends E1, E2 again separated from one another by a respective length dimension of that strip, and a second strip of foam material 300B having a second pair of opposing ends D3, E4 likewise separated from one another by a respective length dimension of that strip. Once again, the length dimension of each strip is its greatest dimension, followed by its width, and finally its thickness, and each strip once again has two opposing faces, each of which spans the length and width dimensions of the strip, and between the two of which the thickness dimension is measured. Like the foam-strip headband of FIG. 17 , preferably the thickness dimension is uniform throughout each strip. On one of its two faces, the first strip 300A has a respective piece of hook or loop fastener 302A, 302B thereon adjacent each of the first pair of opposing ends E1, E2. One of the two faces of the second strip 300B has a respective piece of loop or hook fastener thereon 304A, 304B adjacent each of the second pair of opposing ends E3, E4. The loop or hook fastener material 304A, 304B used on the second strip 300B is of a matable type the hook or loop fastener material 302A, 302B used on the first strip 300A. For example, if hook fastener is used on the first strip, then loop fastener is used on the second strip, or vice versa. Accordingly, the first and second strips are connectable face-to-face in end-overlapping fashion with one another to form a closed loop.

At least one of the pieces of fastener 302A, 302B, 304A, 304B is elongated in the length dimension of the respective strip of foam material to enable coupling together of the two strips in varying degrees of overlap to thereby adjustably size said headband. In the illustrated example, the two fastener pieces 304A, 304B on the second strip 300B are both elongated in the length dimension of that strip. The first strip has two coupling elements 308 installed a mid-region of its length at lengthwise spacing from one another that that matches the known distance between a shield's headband attachment surfaces, whereby the first strip is attachable to a shield at the headband mounting surfaces thereof to form a front section of the overall headband. Once again, each piece of tape 308 includes a respective peel-away cover that is removed to reveal the tape come time for assembly of the headband onto a shield. In other examples, such double-sided tape may instead be applied to the headband attachment surfaces of the shield. As described for the FIG. 17 embodiment, hook and loop fastener may alternatively be used as coupling elements for attaching the headband to the shield. In the illustrated embodiment, the first strip 300A is longer than the second strip 300B, and may be sufficiently long to ensure that when its attached to the headband attachment surfaces of the shield, the ends E1, E2 of the first strip will reach out from the interior space of the shield through the rear opening, thereby placing fastener pieces 302A, 302B outside the shield for easy access. The two ends E3, E4 of the second strip 300B are respectively attachable to these exposed ends E1, E2 of the first strip, in a user-selectable amount of overlap to control the overall size of the closed headband loop co-operably formed by the two connected strips 300A, 300B.

FIG. 18C shows how, after attachment of the first strip 300A to the headband attachment surfaces at the terminal ends of forehead-level protrusions 40A, 40B, a central section of that strip 300A that spans between the two spaced apart protrusions 40A, 40B may be cut out, thus dividing the strip 300A into two separate smaller strips with a gap therebetween. This resulting gap in the front section of the headband leave the airflow space 140 between the two protrusions 40A, 40B fully open at the rear side thereof that faces the user's forehead to maximize the overall available area for airflow between the shield and the user's forehead. The air can now flow through the combined airflow space 140 and headband gap G, rather than only through the shield's original airflow space 140 in front of the installed headband. The same cutting of a central section of the headband to improve overall airflow accommodation can likewise be performed on the installed headband of FIG. 17 , or any other style of strap likewise attached to the forehead-level protrusions 40A, 40B of the shields described herein.

Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense. 

1. A protective shield comprising a transparent non-spherical dome or shell delimiting a hollow interior space for receiving facial and cranial regions of a user's head therein, said non-spherical dome or shell having a boundary edge thereof that delimits an opening of said hollow interior space through which said facial and cranial regions of said user's head are admitted into said hollow interior space, said opening having an elongated primary dimension measured in one direction thereacross and configured with sufficient length to accommodate a chin-to-crown measurement of the user's head in an inferior-superior anatomical direction, and a shorter secondary dimension measured in a cross-wise direction to said primary dimension and configured with sufficient length to accommodate a narrower width measurement of the user's head in a lateral anatomical direction.
 2. The protective shield of claim 1 wherein longitudinally opposing ends of the non-spherical dome or shell reside opposite one another across said elongated primary dimension, and a depth of said hollow interior space is at a maximum at a location nearer to a top one of said longitudinally opposing ends than to a bottom one thereof. 3-6. (canceled)
 7. The protective shield of claim 1 wherein longitudinally opposing ends of the non-spherical dome or shell reside opposite one another across said elongated primary dimension, a depth of said hollow interior space is at a maximum at a location nearer to a top one of the longitudinally opposing ends than to a bottom one thereof, said non-spherical dome or shell, at a region thereof situated across from the opening, comprises at least one inward protrusion jutting into the interior space of the shield relative to surrounding inner surface areas of said dome or shell, and said region at which the at least one protrusion resides is also nearer to said top one of the longitudinally opposing ends than to said bottom one thereof.
 8. (canceled)
 9. The protective shield of claim 1 wherein said non-spherical dome or shell, at a region thereof situated across from the opening, comprises at least one inward protrusion jutting into the interior space of the shield relative to surrounding inner surface areas of said dome or shell, each inward protrusion is coincident with a matching depression in an outer surface of the shield, and each depression is open at top end thereof. 10-14. (canceled)
 15. The protective shield of claim 1 wherein said non-spherical dome or shell, at a region thereof situated across from the opening, comprises a pair of inward protrusions jutting into the interior space of the shield relative to surrounding inner surface areas of said dome or shell, and an airflow space whose width is delimited between said pair of inward protrusions has a widened lower end that coincides with bottom ends of said inward protrusions, and from which said airflow space tapers upwardly to a lesser width than said widened lower end. 16-17. (canceled)
 18. The protective shield of claim 1 wherein height and width dimensions of the dome or shell, measured orthogonally of one another in planes parallel to a reference plane occupied by the opening, are at a maximum at said reference plane.
 19. The protective shield of claim 1 wherein an entirety, or at least a substantial majority, of said boundary edge resides within a singular flat plane.
 20. The protective shield of claim 1 wherein the dome or shell comprises an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, and a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and in a cross-sectional measuring plane that is either a midplane that bisects the dome or shell at a midpoint of the secondary dimension, or another plane that lies parallel to said midplane, a slope of the lower facial portion toward the bottom end of the dome or shell and a slope of the upper cranial portion toward the top end of the of the dome or shell are of divergent relationship to one another over an entirety of each of said upper cranial and lower facial portions.
 21. (canceled)
 22. The protective shield of claim 20 wherein at least over a majority of each of said upper cranial and lower facial portions, a divergence angle between the slopes thereof is greater than 90-degrees. 23-28. (canceled)
 29. The protective shield of claim 20 configured such that, in a worn position on the user's head, the slope of the upper cranial portion is of inclined orientation sloping upwardly toward the boundary edge of the opening. 30-42. (canceled)
 43. The protective shield of claim 1 wherein the dome or shell comprises an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, and a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and said upper cranial portion has an airflow channel formed therein, said airflow channel having opposing inlet and outlet ends situated respectively distally and proximally of the facial region, with the outlet end being open to the interior space of the protective shield at or near the facial region thereof so that airflow fed through the inlet end of the airflow channel is directed into an air space between the shield and the facial region of the user's head.
 44. (canceled)
 45. The protective shield of claim 43 wherein said airflow channel is neighboured on opposing sides by a pair of troughs that are recessed into an exterior of the cranial portion and have respective trough floors, relative to which a ceiling of the airflow channel is of elevated relation. 46-54. (canceled)
 55. The protective shield of claim 1 comprising an out-turned flange projecting from the boundary edge around at least a portion of the opening. 56-78. (canceled)
 79. The protective shield of claim 1 wherein the dome or shell comprises an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and one or more support protrusions that are integrally formed in, or attached to, said cranial portion and jut downwardly from an underside thereof relative to surrounding surface areas of said underside of the cranial portion for resting of said support protrusions against the top of the user's head so as to support said surrounding surface areas in elevated relation over the top of the user's head to enable airflow therebetween.
 80. The protective shield of claim 79 wherein said one or more support protrusions comprise a plurality of support protrusions spaced laterally apart from one another to enable airflow therebetween.
 81. The protective shield claim 79 wherein said one or more support protrusions are elongated in a front-to-rear direction in which said cranial portion extends from said facial portion.
 82. The protective shield of claim 79 wherein said one or more support protrusions coincide with support depressions integrally formed in a topside of the cranial portion.
 83. (canceled)
 84. A one-piece adjustable length headband for support of a protective shield on a users head, said headband comprising a singular unitary strip of foam material having al length dimension in which said strip of foam material is elongated relative to width and thickness dimensions thereof that are orthogonal to both one another and to said length dimension, said strip of foam material having opposing first and second ends between which said length dimension is measured, said strip of foam material having a barbed tail region spanning a partial length of the length dimension from the first end toward the second end, and a widened end region that resides adjacent the second end and is of greater measure in the width dimension than said barbed tail region, said strip of foam material being flexibly bendable in said length dimension to bring the first and second ends toward one another to form a closed loop, said barbed tail region being barbed on opposing sides thereof, and said the widened end region having at least one receiver opening therein through which the first end is insertable to engage the barbed tail through said receiver opening, whereupon the barbed sides of the barbed tail region resist pulling of the first end back through said receiver opening, thereby securing the headband in said closed loop, which is adjustable in size by pulling more of the barbed tail onward through said receiver opening. 85-86. (canceled)
 87. The headband of claim 84 in combination with a protective shield for covering at least a facial region of the user's head, said protective shield, at an elevation configured to reside at approximately forehead level on the user's head when worn, having at least one inward protrusion jutting from surrounding inner surface areas of said protective shield so as to span toward and brace against a forehead of the user's head when worn, wherein the strip of foam material has two faces that oppose on another in the thickness dimension, at the combination further comprises one or more coupling elements positioned on at least one of either a respective terminal end of each inward protrusion, or a respective one of the two faces of said strip of foam material, said one or more coupling elements being operable to secure said one of the two faces of said strip of foam material to said respective terminal end of each inward protrusion, thereby securing said protective shield to said headband.
 88. A method of using the combination of claim 87 wherein the at least one inward protrusion comprises a pair of inward protrusions, and the one or more coupling elements comprises a pair of coupling elements by which the strip of foam material is attached to said pair of inward protrusions, said method comprises cutting out a section of said strip of foam between said pair of inward protrusions, to enable airflow through said cut out section of the headband.
 89. A two-piece adjustable length headband for support of a protective shield on a users head, said headband comprising a first strip of foam material having a first pair of opposing ends separated from one another by a length dimension of said first strip of foam material, and a second strip of foam material having a second pair of opposing ends separated from one another by a length dimension of said second strip of foam material, one of two widthwise faces of the first strip having a respective piece of hook or loop fastener thereon adjacent each of the first pair of opposing ends, and one of two widthwise faces of the second strip having a respective piece of loop or hook fastener thereon adjacent each of the second pair of opposing ends that is matable with one of the hook or loop fasteners on the first strip, whereby the first and second strips are connectable face-to-face in end-overlapping fashion to form a closed loop, and at least one of the pieces of fastener is elongated in the length dimension of the respective strip of foam material to enable coupling together of the two strips in varying degrees of overlap to thereby adjustably size said headband.
 90. The headband of claim 89 in combination with a protective shield for covering at least a facial region of the user's head, said protective shield, at an elevation configured to reside at approximately forehead level on the user's head when worn, having at least one inward protrusion jutting from surrounding inner surface areas of said protective shield so as to span toward and brace against a forehead of the user's head when worn, wherein the combination further comprises one or more coupling elements positioned on at least one of either a respective terminal end of each inward protrusion, or on one of the two widthwise faces of one of the first or second strips of foam material, said one or more coupling elements being operable to secure said one of the first or second strips of foam material to said respective terminal end of each inward protrusion, thereby securing said protective shield to said headband.
 91. (canceled)
 92. (canceled)
 93. (canceled)
 94. The protective shield of claim 1 in combination with a headband, wherein said non-spherical dome or shell, at a region thereof situated across from the opening, comprises a pair of inward protrusions that jut into the interior space of the shield relative to surrounding inner surface areas of said dome or shell and are spaced apart from one another in the cross-wise direction to leave an airflow space therebetween, foam portions of the headband are attached to terminal ends the inward protrusions to support the protective shield on said headband, and said headband spans a less than full loop, and has a open gap therein between the pair of inward protrusions, whereby the open gap of the headband enlarges an effective size of the airflow space between the inward protrusions to maximize airflow therethrough.
 95. The protective shield of claim 1 wherein the dome or shell comprises an upper cranial portion arranged to overlie a top of the user's head, at least at a frontal scalp thereof, a lower facial portion arranged to hang downwardly from the cranial portion over the facial region of the user's head, and at a transitional region that joins said lower facial and upper cranial portions, at approximately forehead level when said protective shield is worn, at least one inward protrusion jutting inwardly from the transitional region relative to surrounding inner surface areas thereof, wherein, in a cross-sectional measuring plane that is parallel to a midplane that bisects the cranial and facial regions, at least a partial region of the lower facial portion has a linear slope, and at least a partial surface of a distal end each inward protrusion has a relative slope of obliquely oriented and downwardly convergent relationship to said linear slope of the lower facial portion.
 96. (canceled)
 99. The protective shield of claim 95 in combination with a headband attached to the distal end of the of the at least one inward protrusion at an area thereof possessing said relative slope, wherein the obliquely oriented and downwardly convergent relationship between the linear slope of the lower facial portion and the relative slope at the distal end of the at least one inward protrusion is configured such that, when the protective shield is worn on the user's head in supported fashion by said headband, the linear slope of the lower facial portion angles downwardly rearward toward a chest of the user. 